Structure 16101900010000 · Hillsborough County, NH

Nh 28 S Willow ST over Cohas Brook

Carries Nh 28 S Willow ST over Cohas Brook, 1.2 Mi N Londonderry Tl.

Overall conditionFair

Set by its lowest-rated component: Culvert at 6 of 9.

How ratings work
Culvertsets the rating6/9 · Satisfactory
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT37 FT ACROSS25 FT0ELEVATION · LENGTHS TO SCALE
Culvert 6/9

A culvert 37 ft across. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.

Built198937 years old
Length37.1 ft11.3 m
Daily traffic16,239counted 2023
Last inspectedJuly 2024every 24 months

Location

StateNew Hampshire
CountyHillsborough
Location1.2 Mi N Londonderry Tl
CarriesNh 28 S Willow ST
CrossesCohas Brook
Coordinates42.94702, -71.43330

Physical Characteristics

MaterialConcrete
DesignCulvert
Total Length37.1 ft (11.3 m)
Max Span32.2 ft (9.8 m)
Deck Area96.0 sq m
Main Spans1
Year Built1989

Traffic

Avg Daily Traffic16,239 (2023)
Truck Traffic5%
Lanes On Bridge5

Inspection & Ownership

Last InspectionJuly 2024
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number016101900010000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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